National Fenestration Rating Council

The National Fenestration Rating Council (NFRC) is a nonprofit, public/private organization created by the window, door, and skylight industry. It is composed of manufacturers, suppliers, researchers, architects and designers, code officials, utilities, and government agencies. The NFRC has developed a fenestration energy rating system based on whole product performance.

NFRC ratings are crucial for energy code compliance. Building energy codes require certified fenestration energy ratings determined in accordance with NFRC standards by accredited laboratories. The NFRC standards referenced in the codes are for the following whole-product energy ratings:

U-factor

Solar Heat Gain Coefficient (SHGC)

Visible Transmittance (VT)

Air Leakage (AL)

Air leakage can alternatively be determined in accordance with the North American Fenestration Standard.